diff options
Diffstat (limited to 'drivers/cxl/acpi.c')
| -rw-r--r-- | drivers/cxl/acpi.c | 539 |
1 files changed, 539 insertions, 0 deletions
diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c new file mode 100644 index 000000000..dd610556a --- /dev/null +++ b/drivers/cxl/acpi.c @@ -0,0 +1,539 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2021 Intel Corporation. All rights reserved. */ +#include <linux/platform_device.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/acpi.h> +#include <linux/pci.h> +#include "cxlpci.h" +#include "cxl.h" + +static unsigned long cfmws_to_decoder_flags(int restrictions) +{ + unsigned long flags = CXL_DECODER_F_ENABLE; + + if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE2) + flags |= CXL_DECODER_F_TYPE2; + if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE3) + flags |= CXL_DECODER_F_TYPE3; + if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE) + flags |= CXL_DECODER_F_RAM; + if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_PMEM) + flags |= CXL_DECODER_F_PMEM; + if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_FIXED) + flags |= CXL_DECODER_F_LOCK; + + return flags; +} + +static int cxl_acpi_cfmws_verify(struct device *dev, + struct acpi_cedt_cfmws *cfmws) +{ + int rc, expected_len; + unsigned int ways; + + if (cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_MODULO) { + dev_err(dev, "CFMWS Unsupported Interleave Arithmetic\n"); + return -EINVAL; + } + + if (!IS_ALIGNED(cfmws->base_hpa, SZ_256M)) { + dev_err(dev, "CFMWS Base HPA not 256MB aligned\n"); + return -EINVAL; + } + + if (!IS_ALIGNED(cfmws->window_size, SZ_256M)) { + dev_err(dev, "CFMWS Window Size not 256MB aligned\n"); + return -EINVAL; + } + + rc = cxl_to_ways(cfmws->interleave_ways, &ways); + if (rc) { + dev_err(dev, "CFMWS Interleave Ways (%d) invalid\n", + cfmws->interleave_ways); + return -EINVAL; + } + + expected_len = struct_size(cfmws, interleave_targets, ways); + + if (cfmws->header.length < expected_len) { + dev_err(dev, "CFMWS length %d less than expected %d\n", + cfmws->header.length, expected_len); + return -EINVAL; + } + + if (cfmws->header.length > expected_len) + dev_dbg(dev, "CFMWS length %d greater than expected %d\n", + cfmws->header.length, expected_len); + + return 0; +} + +struct cxl_cfmws_context { + struct device *dev; + struct cxl_port *root_port; + struct resource *cxl_res; + int id; +}; + +static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, + const unsigned long end) +{ + int target_map[CXL_DECODER_MAX_INTERLEAVE]; + struct cxl_cfmws_context *ctx = arg; + struct cxl_port *root_port = ctx->root_port; + struct resource *cxl_res = ctx->cxl_res; + struct cxl_root_decoder *cxlrd; + struct device *dev = ctx->dev; + struct acpi_cedt_cfmws *cfmws; + struct cxl_decoder *cxld; + unsigned int ways, i, ig; + struct resource *res; + int rc; + + cfmws = (struct acpi_cedt_cfmws *) header; + + rc = cxl_acpi_cfmws_verify(dev, cfmws); + if (rc) { + dev_err(dev, "CFMWS range %#llx-%#llx not registered\n", + cfmws->base_hpa, + cfmws->base_hpa + cfmws->window_size - 1); + return 0; + } + + rc = cxl_to_ways(cfmws->interleave_ways, &ways); + if (rc) + return rc; + rc = cxl_to_granularity(cfmws->granularity, &ig); + if (rc) + return rc; + for (i = 0; i < ways; i++) + target_map[i] = cfmws->interleave_targets[i]; + + res = kzalloc(sizeof(*res), GFP_KERNEL); + if (!res) + return -ENOMEM; + + res->name = kasprintf(GFP_KERNEL, "CXL Window %d", ctx->id++); + if (!res->name) + goto err_name; + + res->start = cfmws->base_hpa; + res->end = cfmws->base_hpa + cfmws->window_size - 1; + res->flags = IORESOURCE_MEM; + + /* add to the local resource tracking to establish a sort order */ + rc = insert_resource(cxl_res, res); + if (rc) + goto err_insert; + + cxlrd = cxl_root_decoder_alloc(root_port, ways); + if (IS_ERR(cxlrd)) + return 0; + + cxld = &cxlrd->cxlsd.cxld; + cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions); + cxld->target_type = CXL_DECODER_EXPANDER; + cxld->hpa_range = (struct range) { + .start = res->start, + .end = res->end, + }; + cxld->interleave_ways = ways; + /* + * Minimize the x1 granularity to advertise support for any + * valid region granularity + */ + if (ways == 1) + ig = CXL_DECODER_MIN_GRANULARITY; + cxld->interleave_granularity = ig; + + rc = cxl_decoder_add(cxld, target_map); + if (rc) + put_device(&cxld->dev); + else + rc = cxl_decoder_autoremove(dev, cxld); + if (rc) { + dev_err(dev, "Failed to add decode range: %pr", res); + return rc; + } + dev_dbg(dev, "add: %s node: %d range [%#llx - %#llx]\n", + dev_name(&cxld->dev), + phys_to_target_node(cxld->hpa_range.start), + cxld->hpa_range.start, cxld->hpa_range.end); + + return 0; + +err_insert: + kfree(res->name); +err_name: + kfree(res); + return -ENOMEM; +} + +__mock struct acpi_device *to_cxl_host_bridge(struct device *host, + struct device *dev) +{ + struct acpi_device *adev = to_acpi_device(dev); + + if (!acpi_pci_find_root(adev->handle)) + return NULL; + + if (strcmp(acpi_device_hid(adev), "ACPI0016") == 0) + return adev; + return NULL; +} + +/* + * A host bridge is a dport to a CFMWS decode and it is a uport to the + * dport (PCIe Root Ports) in the host bridge. + */ +static int add_host_bridge_uport(struct device *match, void *arg) +{ + struct cxl_port *root_port = arg; + struct device *host = root_port->dev.parent; + struct acpi_device *bridge = to_cxl_host_bridge(host, match); + struct acpi_pci_root *pci_root; + struct cxl_dport *dport; + struct cxl_port *port; + int rc; + + if (!bridge) + return 0; + + dport = cxl_find_dport_by_dev(root_port, match); + if (!dport) { + dev_dbg(host, "host bridge expected and not found\n"); + return 0; + } + + /* + * Note that this lookup already succeeded in + * to_cxl_host_bridge(), so no need to check for failure here + */ + pci_root = acpi_pci_find_root(bridge->handle); + rc = devm_cxl_register_pci_bus(host, match, pci_root->bus); + if (rc) + return rc; + + port = devm_cxl_add_port(host, match, dport->component_reg_phys, dport); + if (IS_ERR(port)) + return PTR_ERR(port); + + return 0; +} + +struct cxl_chbs_context { + struct device *dev; + unsigned long long uid; + resource_size_t chbcr; +}; + +static int cxl_get_chbcr(union acpi_subtable_headers *header, void *arg, + const unsigned long end) +{ + struct cxl_chbs_context *ctx = arg; + struct acpi_cedt_chbs *chbs; + + if (ctx->chbcr) + return 0; + + chbs = (struct acpi_cedt_chbs *) header; + + if (ctx->uid != chbs->uid) + return 0; + ctx->chbcr = chbs->base; + + return 0; +} + +static int add_host_bridge_dport(struct device *match, void *arg) +{ + acpi_status status; + unsigned long long uid; + struct cxl_dport *dport; + struct cxl_chbs_context ctx; + struct cxl_port *root_port = arg; + struct device *host = root_port->dev.parent; + struct acpi_device *bridge = to_cxl_host_bridge(host, match); + + if (!bridge) + return 0; + + status = acpi_evaluate_integer(bridge->handle, METHOD_NAME__UID, NULL, + &uid); + if (status != AE_OK) { + dev_err(host, "unable to retrieve _UID of %s\n", + dev_name(match)); + return -ENODEV; + } + + ctx = (struct cxl_chbs_context) { + .dev = host, + .uid = uid, + }; + acpi_table_parse_cedt(ACPI_CEDT_TYPE_CHBS, cxl_get_chbcr, &ctx); + + if (ctx.chbcr == 0) { + dev_warn(host, "No CHBS found for Host Bridge: %s\n", + dev_name(match)); + return 0; + } + + dport = devm_cxl_add_dport(root_port, match, uid, ctx.chbcr); + if (IS_ERR(dport)) { + dev_err(host, "failed to add downstream port: %s\n", + dev_name(match)); + return PTR_ERR(dport); + } + dev_dbg(host, "add dport%llu: %s\n", uid, dev_name(match)); + return 0; +} + +static int add_root_nvdimm_bridge(struct device *match, void *data) +{ + struct cxl_decoder *cxld; + struct cxl_port *root_port = data; + struct cxl_nvdimm_bridge *cxl_nvb; + struct device *host = root_port->dev.parent; + + if (!is_root_decoder(match)) + return 0; + + cxld = to_cxl_decoder(match); + if (!(cxld->flags & CXL_DECODER_F_PMEM)) + return 0; + + cxl_nvb = devm_cxl_add_nvdimm_bridge(host, root_port); + if (IS_ERR(cxl_nvb)) { + dev_dbg(host, "failed to register pmem\n"); + return PTR_ERR(cxl_nvb); + } + dev_dbg(host, "%s: add: %s\n", dev_name(&root_port->dev), + dev_name(&cxl_nvb->dev)); + return 1; +} + +static struct lock_class_key cxl_root_key; + +static void cxl_acpi_lock_reset_class(void *dev) +{ + device_lock_reset_class(dev); +} + +static void del_cxl_resource(struct resource *res) +{ + kfree(res->name); + kfree(res); +} + +static void cxl_set_public_resource(struct resource *priv, struct resource *pub) +{ + priv->desc = (unsigned long) pub; +} + +static struct resource *cxl_get_public_resource(struct resource *priv) +{ + return (struct resource *) priv->desc; +} + +static void remove_cxl_resources(void *data) +{ + struct resource *res, *next, *cxl = data; + + for (res = cxl->child; res; res = next) { + struct resource *victim = cxl_get_public_resource(res); + + next = res->sibling; + remove_resource(res); + + if (victim) { + remove_resource(victim); + kfree(victim); + } + + del_cxl_resource(res); + } +} + +/** + * add_cxl_resources() - reflect CXL fixed memory windows in iomem_resource + * @cxl_res: A standalone resource tree where each CXL window is a sibling + * + * Walk each CXL window in @cxl_res and add it to iomem_resource potentially + * expanding its boundaries to ensure that any conflicting resources become + * children. If a window is expanded it may then conflict with a another window + * entry and require the window to be truncated or trimmed. Consider this + * situation: + * + * |-- "CXL Window 0" --||----- "CXL Window 1" -----| + * |--------------- "System RAM" -------------| + * + * ...where platform firmware has established as System RAM resource across 2 + * windows, but has left some portion of window 1 for dynamic CXL region + * provisioning. In this case "Window 0" will span the entirety of the "System + * RAM" span, and "CXL Window 1" is truncated to the remaining tail past the end + * of that "System RAM" resource. + */ +static int add_cxl_resources(struct resource *cxl_res) +{ + struct resource *res, *new, *next; + + for (res = cxl_res->child; res; res = next) { + new = kzalloc(sizeof(*new), GFP_KERNEL); + if (!new) + return -ENOMEM; + new->name = res->name; + new->start = res->start; + new->end = res->end; + new->flags = IORESOURCE_MEM; + new->desc = IORES_DESC_CXL; + + /* + * Record the public resource in the private cxl_res tree for + * later removal. + */ + cxl_set_public_resource(res, new); + + insert_resource_expand_to_fit(&iomem_resource, new); + + next = res->sibling; + while (next && resource_overlaps(new, next)) { + if (resource_contains(new, next)) { + struct resource *_next = next->sibling; + + remove_resource(next); + del_cxl_resource(next); + next = _next; + } else + next->start = new->end + 1; + } + } + return 0; +} + +static int pair_cxl_resource(struct device *dev, void *data) +{ + struct resource *cxl_res = data; + struct resource *p; + + if (!is_root_decoder(dev)) + return 0; + + for (p = cxl_res->child; p; p = p->sibling) { + struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev); + struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld; + struct resource res = { + .start = cxld->hpa_range.start, + .end = cxld->hpa_range.end, + .flags = IORESOURCE_MEM, + }; + + if (resource_contains(p, &res)) { + cxlrd->res = cxl_get_public_resource(p); + break; + } + } + + return 0; +} + +static int cxl_acpi_probe(struct platform_device *pdev) +{ + int rc; + struct resource *cxl_res; + struct cxl_port *root_port; + struct device *host = &pdev->dev; + struct acpi_device *adev = ACPI_COMPANION(host); + struct cxl_cfmws_context ctx; + + device_lock_set_class(&pdev->dev, &cxl_root_key); + rc = devm_add_action_or_reset(&pdev->dev, cxl_acpi_lock_reset_class, + &pdev->dev); + if (rc) + return rc; + + cxl_res = devm_kzalloc(host, sizeof(*cxl_res), GFP_KERNEL); + if (!cxl_res) + return -ENOMEM; + cxl_res->name = "CXL mem"; + cxl_res->start = 0; + cxl_res->end = -1; + cxl_res->flags = IORESOURCE_MEM; + + root_port = devm_cxl_add_port(host, host, CXL_RESOURCE_NONE, NULL); + if (IS_ERR(root_port)) + return PTR_ERR(root_port); + + rc = bus_for_each_dev(adev->dev.bus, NULL, root_port, + add_host_bridge_dport); + if (rc < 0) + return rc; + + rc = devm_add_action_or_reset(host, remove_cxl_resources, cxl_res); + if (rc) + return rc; + + ctx = (struct cxl_cfmws_context) { + .dev = host, + .root_port = root_port, + .cxl_res = cxl_res, + }; + rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, cxl_parse_cfmws, &ctx); + if (rc < 0) + return -ENXIO; + + rc = add_cxl_resources(cxl_res); + if (rc) + return rc; + + /* + * Populate the root decoders with their related iomem resource, + * if present + */ + device_for_each_child(&root_port->dev, cxl_res, pair_cxl_resource); + + /* + * Root level scanned with host-bridge as dports, now scan host-bridges + * for their role as CXL uports to their CXL-capable PCIe Root Ports. + */ + rc = bus_for_each_dev(adev->dev.bus, NULL, root_port, + add_host_bridge_uport); + if (rc < 0) + return rc; + + if (IS_ENABLED(CONFIG_CXL_PMEM)) + rc = device_for_each_child(&root_port->dev, root_port, + add_root_nvdimm_bridge); + if (rc < 0) + return rc; + + /* In case PCI is scanned before ACPI re-trigger memdev attach */ + return cxl_bus_rescan(); +} + +static const struct acpi_device_id cxl_acpi_ids[] = { + { "ACPI0017" }, + { }, +}; +MODULE_DEVICE_TABLE(acpi, cxl_acpi_ids); + +static const struct platform_device_id cxl_test_ids[] = { + { "cxl_acpi" }, + { }, +}; +MODULE_DEVICE_TABLE(platform, cxl_test_ids); + +static struct platform_driver cxl_acpi_driver = { + .probe = cxl_acpi_probe, + .driver = { + .name = KBUILD_MODNAME, + .acpi_match_table = cxl_acpi_ids, + }, + .id_table = cxl_test_ids, +}; + +module_platform_driver(cxl_acpi_driver); +MODULE_LICENSE("GPL v2"); +MODULE_IMPORT_NS(CXL); +MODULE_IMPORT_NS(ACPI); |